scsi: mpi3mr: Fix corrupt config pages PHY state is switched in sysfs

scsi: mpi3mr: Fix corrupt config pages PHY state is switched in sysfs

The driver, through the SAS transport, exposes a sysfs interface to
enable/disable PHYs in a controller/expander setup.  When multiple PHYs
are disabled and enabled in rapid succession, the persistent and current
config pages related to SAS IO unit/SAS Expander pages could get
corrupted.

Use separate memory for each config request.

Signed-off-by: Prayas Patel <prayas.patel@broadcom.com>
Signed-off-by: Ranjan Kumar <ranjan.kumar@broadcom.com>
Link: https://lore.kernel.org/r/20241110194405.10108-3-ranjan.kumar@broadcom.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>